[TenTec] 756 Icom keying Titan 425 amp?

[hogman at ev1.net]

Need some help on getting the Titan to key up using the Icom 756!    My
Icom hr has only one outgoing keying line,    but the Titan requires two
lines!    Why seems a bit silly for that!    Yes I know the PTT/VOX plug
needs to used,  but it still doesnt key the amp!    And my manual here
doesnt seem to cover it very well!
Any tips would be greatly appreciated!

thanks,    Steve/WD5HNI